VulnHunter
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VulnHunter is an open-source agentic AI security tool that applies attacker-first analysis to source code to identify exploitable vulnerabilities.
claude --model opus --add-dir ~/.claude/skills/vulnhunt --add-dir ~/.claude/skills/vulnhunt/phases
# Then inside the Claude Code session:
/vulnhunt
claude --model opus --add-dir ~/.claude/skills/vulnhunt-fix-verify \
--add-dir ~/.claude/skills/vulnhunt-fix-verify/phases
# Then inside the Claude Code session:
/vulnhunt-fix-verify repo=<abs_path> report=<abs_path> fixed=VULN-001,... out=<abs_path>
cd harness
python -m local_harness.batch.run scan --resume
python -m local_harness.batch.run collect
claude --model opus --add-dir ~/.claude/skills/vulnhunt --add-dir ~/.claude/skills/vulnhunt/phases
# Then inside the Claude Code session:
/vulnhunt
claude --model opus --add-dir ~/.claude/skills/vulnhunt-fix-verify \
--add-dir ~/.claude/skills/vulnhunt-fix-verify/phases
# Then inside the Claude Code session:
/vulnhunt-fix-verify repo=<abs_path> report=<abs_path> fixed=VULN-001,... out=<abs_path>
cd harness
python -m local_harness.batch.run scan --resume
python -m local_harness.batch.run collect
Summary
VulnHunter is an open-source, agentic AI security tool that runs as a set of Claude Code skills for finding and fixing exploitable vulnerabilities in source code. Rather than flagging suspicious patterns like a passive SASTSASTStatic application security testing, analyzing source code or compiled code for vulnerabilities without running the application. It helps developers find problems before deployment. scanner, it works forward from attacker-accessible entry points, tracing paths to dangerous sinks and filtering results through a multi-stage falsification pipeline before proposing fixes, so it targets application security and appsec engineering teams who want fewer false positives than conventional static analysis. It requires Opus-class model access supplied by the user, and can run headless in CI/CD pipelines via its agent runtime, or in batch mode across many repositories using its harness tooling. Developed internally at Capital One before release to the community, it is a young project — first committed in 2026, with four contributors and one release so far, though that release landed just over a month ago.
VulnHunter is an open-source agentic AI security tool that applies attacker-first analysis to source code to identify exploitable vulnerabilities.
How VulnHunter helps
Which entry points in this codebase could an attacker actually reach, and where do they lead?
starts from APIs, network messages, and file uploads and traces each one forward through the code to the dangerous sinks it can reach, rather than starting from the sink and guessing backward
Which of these findings are real, exploitable bugs rather than noise?
pushes every candidate through a multi-stage pipeline — recon, parallel hunting, adversarial disproof, and a capability filter — before it's reported, so what survives has been actively argued against, not just pattern-matched
Is this vulnerability actually fixed, or does the patch just look right?
a separate read-only agent re-runs the original exploit path against the patched code and issues its own pass/fail verdict, independent of whichever process produced the fix
How do I get from a confirmed finding to a mergeable fix without doing it by hand?
writes a failing security test that demonstrates the exploit, implements the smallest fix that turns it green, confirms the exploit is now blocked, and opens a pull request with that evidence attached
Which of the repositories I'm responsible for actually have exploitable issues, not just which ones have code smells?
runs the same attacker-first scan across a whole list of repositories, resuming where a previous batch left off, and centralizes every confirmed finding for review in one place
How accurate is this against vulnerabilities I already know are there?
the benchmarking harness runs the scanner against a corpus of known-vulnerable code and scores detection accuracy with an LLM judge, giving a measured baseline instead of a claimed one
Languages
Command line
| option | found in | since | description |
|---|
Values are placeholders taken from each option’s declared default. Nothing is executed here — the output shown is a recording of a run that already happened.
Score card
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Shipping velocity releases a month, last 12 months
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Documentation quality release-notes rubric, 0–100
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Breaking-change discipline how rarely a release breaks users, and notice given
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Maintenance risk quiet time against its own cadence, maintainers
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Innovation & surface new capabilities, API and MCP surface
- Community health
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Contributor trend distinct committers, this year against last
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Maintainer concentration bus factor now against a year ago
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Issue backlog trend issues closed per issue opened, 12 months
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Responsiveness median time to a maintainer’s first reply
Nine scores for VulnHunter, each built from the releases, notes and API history this site tracks — and, on Researcher and Business, where it stands among every measured tool in its category and how that has moved.
Score cards are part of every paid plan.
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Blank means never measured; nothing here is a filled-in zero.
Peer standings are included with Researcher and Business. See how this tool ranks against its competitors, using data we don't publish anywhere else.
See plans →Each score is 0–100 on a published rubric, derived from data this site already shows. A dimension we cannot measure says so — it is never scored 0 and never enters a rank.
How this is scored
- Shipping velocity — releases a month over the last 12 months, on a log scale where 16 a month scores 100. Needs 3 releases in the window.
- Documentation quality — the release-notes rubric published on the analytics page, unchanged.
- Breaking-change discipline — the share of releases carrying a breaking change (none scores 100, half or more scores 0). Only projects that label breaking changes are measured: a clean record cannot be told from an unlabelled one.
- Maintenance risk — quiet time measured against the tool's own release cadence (quiet longer than 90 days and three typical gaps scores 0), plus the number of active maintainers and whether contributors are growing, where known. Higher is lower risk.
- Innovation & surface — new capabilities in the feature ledger this year, API and MCP operations added, and the share of commits that are features: the mean of whichever we hold.
- Community health (open-source tools only) — each is a direction, not a size: contributors this year against last, the bus factor now against a year ago, and issues closed per issue opened, where steady scores 50, doubled 100 and halved 0; plus the median time to a maintainer's first reply (an hour scores about 100, a month or more 0). A commercial card has no repository and carries none of the four.
- Documented delivery (commercial tools) — when a vendor's documented new capabilities have slowed against its own baseline, that counts against the overall standing as heavily as two low dimensions. Steady delivery, or too little history to judge, leaves the standing alone; it is never a sixth score.
- Open-source tools are scored on repository signals; commercial tools on their published changelog. Ranks compare tools within one category and one profile and need at least five measured peers; the overall standing needs three ranked dimensions. Best-in-breed or consolidator is a shape, not a quality, and is never scored.
Release-note detail over time
See how much detail VulnHunter puts in its release notes, quarter by quarter, and compare it with tracked tools in the same category. This history uses up to ten retained, reviewed notes per tool; sparse or blank older quarters may reflect that limit.
Checking release-note history…
Releases
2 entries
No entries match these filters.
- July 20262
Project health
Issue, contributor and maintainer activity in capitalone/VulnHunter, 2023-10 – 2026-09, as of 2026-09-25. Twelve-month figures first; the trend lines run the whole window.
- Contributors 7 +7 vs prior 12 months
- Maintainers 2 +2 joined · −0 left, last 12 months
- Bus factor 1 committers behind half the commits
- Community-filed 100% of issues opened, last 12 months
- Median time to close 11 days first maintainer reply 11 days
- Open backlog 3 of 4 issues ever filed
- Issues opened / month 1 · 0 communitymaintainers
- Open backlog 3
- Contributors / month 0
- Commits / month 0
- Stars 1,008
- other 100%
Counts from the project's public repository and git history; no individuals are identified. Maintainers are the committers covering 80% of the last year's commits. how we measure this
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